A 65-year old male was referred to the emergency room for an acute ST segment elevation myocardial infarction (ASTEMI) that occurred 5 hours previously. The patient complained of persistent chest pain after thrombolysis at the local hospital. An electrocardiogram (ECG) revealed ST segment elevation on the precordial leads (V2-V5) and the inferior leads (II, III, aVF). There was an increase in both the creatine kinase-MB fraction (256 µg/L) and cardiac troponin-I level (12.2 ng/mL). Based on these results an emergency coronary angiography was performed. The angiography revealed the presence of a total occlusion of the middle left anterior descending coronary artery (LAD) and a fistula originating from the proximal LAD to the main pulmonary artery (Fig. A and B). The patient had a small right coronary artery, a large LAD and a large left circumflex coronary artery. Therefore, a primary percutaneous coronary intervention (PCI) was performed in the middle LAD with a paclitaxel eluting stent (TAXUS, Boston Scientifics, Natick, MA, USA). No abnormalities were found in the distal LAD after the PCI (Fig. C). The follow up coronary angiography showed a fistula from the septal branches of the distal LAD to the right ventricle (RV) and mild aneurysmal changes at the stent site in the middle LAD after 9 months (Fig. D).1)2) The transthoracic echocardiography revealed a focal diastolic flow within the RV chamber (Fig. E and F). The patient had no discomfort. The presence of a fistula from coronary artery to RV after an ASTEMI and aneurysmal changes in a paclitaxel eluting stent are very rare. This may have developed as a result of myocardial necrosis after the ASTEMI and the left dominant coronary system may have contributed to the fistula from the distal LAD to the RV.3)4)